Intra-abdominal desmoid tumors mimicking gastrointestinal stromal tumors — 8 cases: A case report

Figure 2 Histological examination of intra-abdominal desmoid tumors in patients with gastrointestinal stromal tumors showed low or moderate cellularity with proliferative spindle cells in a fibrotic background and infiltrative growth patterns (hematoxylin and eosin, original magnification × 400). Tumor cells were negative for CD117 and DOG-1, whereas positive for β-catenin. A: Patient 7: A 40-year-old female patient presented with small bowel gastrointestinal stromal tumors (GIST) with metastasis in the peritoneum, liver, and ovary. She underwent initial debulking surgery. GIST cells were positive for CD117; B: Desmoid tumor (DT) in the pelvic peritoneum showed low cellularity with collagen fibers and was negative for CD117; C: DT was positive for β-catenin; D: DT was negative for DOG-1. GIST: Gastrointestinal stromal tumors; DT: Desmoid tumor.